黄河三角洲实验区表层沉积物重金属污染特征及防控策略

Characteristics and control strategies of heavy metal pollution in surfacesediments of the Yellow River Delta experimental zone

分析了黄河三角洲实验区内表层沉积物中重金属的空间分布特征,评价了其污染状况和生态风险,并根据评价结果提出了相应的重金属污染防控措施。结果表明:表层沉积物(0~20 cm)中Cu、Zn、Cr、Cd、Pb、Ni、As和Hg的平均质量分数分别为24.87,73.75,78.16,0.21,25.66,34.66,13.68,0.02 mg·kg^(-1);各重金属均呈现南岸高于北岸的空间分布特征,且所有元素质量分数的最高值均出现在景区“鸟岛”处;内梅罗综合污染指数分析表明,鸟岛属于中污染到重污染,其余采样点均为轻污染;地累积指数评价表明沉积物中Cd和Hg污染相对严重;潜在生态风险指数表明研究区总体属于轻微-中等生态危害。黄河三角洲邻近核心区的实验区表层沉积物中重金属综合污染程度较低,但存在局部污染较重的区域,Cd和Hg是主要的潜在生态风险因子。基于以上研究结果,建议针对黄河三角洲实验区采取预防为主的防控策略,同时应加强区内Cd和Hg的监测并适时开展修复工作。

This study was to investigate the spatial distribution characteristics for the selected heavy metals in surface sediments from the experimental zone of the Yellow River delta and evaluate their pollution condition and ecological risks.The results showed that the average concentration of Cu,Zn,Cr,Cd,Pb,Ni,As,and Hg in surface sediments(0~20 cm)were 24.87,73.75,78.16,0.21,25.66,34.66,13.68,and 0.02 mg·kg^(-1),respectively.The contents of selected heavy metals were higher in the surface sediment from the south bank than that from the north bank,while the maximum contents of metals were observed at scenic spot“Bird Island”located on the south bank.According to the analysis of the Nemerow Integrated Pollution Index(IPI),Bird Island was classified as being in the range of moderate to heavy pollution,while the rest of the sampling points were classified as light pollution.In addition,the Ground Accumulation Index(GAI)indicated that Cd and Hg contamination in the surface sediments were relatively serve.The Potential Ecological Risk Index(PERI)implied that the overall ecological hazard in the study area was categorized as slight to moderate.In summary,the pollution of heavy metals in surface sediments from the experimental zone of the Yellow River Delta was relatively low.However,Cd and Hg were the main potential ecological risk factors in the specific site with intensive heavy metal pollution.Based on the above findings,this study suggested that the prevention strategy should be adopted in the experimental area of Yellow River Delta,and the prevention,control and restoration of Cd and Hg should be strengthened.